Originally posted by rev
Head gaskets are designed to be used for an oversized bore already, so just use the one you get from the dealer/parts store.
Word. Honda makes pistons in .25 and .5mm overbore, but they don't have overbore head gasket part numbers, so the same gasket works with all of them. I would personally run an OEM gasket and spray it with a couple coats of copper spray. The OEM Y8 gasket is only like $20. If you really want a Cometic, you can get them from a lot of places. You'll probably want the HP gasket, which basically has o-rings to help seal the combustion chambers.
http://www.nipponpower.com/engine/ga...ometic_hp.html
http://www.raceeng.com/ShowSuppliers...=IMP&subcat=GS